In laparoscopic surgical procedures, a small incision is made in the body and an elongate shaft of a surgical device is inserted through the incision to position a distal end of the shaft at a surgical site. In endoscopic procedures, the elongate shaft of a surgical device is inserted through a natural orifice, such as the mouth or anus, and is advanced along a pathway to position a distal end of the device at a surgical site. Endoscopic procedures typically require the use of a flexible shaft to accommodate the tortuous pathway of the body lumen, whereas rigid shafts can be used in laparoscopic procedures. These tools can be used to engage and/or treat tissue in a number of ways to achieve a diagnostic or therapeutic effect.
Often during laparoscopic and endoscopic procedures, a surgeon must grasp, ablate, manipulate, dissect, or clamp soft tissue. Such actions may be performed using a plier-like tool, such as a hemostat or forceps. In some circumstances, the working end of the tool includes a first electrode and a second electrode, where one of the electrodes is brought into close opposition to the other electrode, thereby allowing an electrical current to pass between the two conductive elements. When soft tissue is captured between the two electrodes, the flowing current can cauterize, vaporize, and/or otherwise treat the soft tissue. Previous bipolar forceps, referring to U.S. Pat. No. 5,944,718, the entire disclosure of which is hereby incorporated be reference herein, have included a first electrode which can be angularly pivoted relative to a stationary second electrode. These forceps have further included a first wire attached to the first electrode where the first wire is configured to supply current to the first electrode from an electrical source. In addition, these forceps have included a second wire which is attached to the second electrode where the second wire is configured to complete the electrical circuit and return the current back to the electrical source. In some circumstances the working end of the tool includes a cutting end with a first blade member and second blade member to allow for the cutting, severing, or dissection of soft tissue. In some circumstances the working end of the tool includes a plurality of teeth to assist in the gripping of tissue.
Generally, these laparoscopic and endoscopic devices require a linkage associated with the working end of the devices which allows for user-controlled operation. The linkage allows the user to move the jaws of the working end between an open position and a closed position. An open position is when the jaws are disposed in spaced relation to one another and a closed position is wherein the jaw members cooperate to grasp tissue therebetween. These linkages used to control the movement of the jaws can often be complex requiring a multitude of small components. Additionally, in some circumstances, such linkages may not provide the desired clamping force or opening force during surgical procedures.
Accordingly, there remains a need for improved methods and devices for controlling actuation of a working end of a surgical device.